Push-ups: Depending on your upper body strength, place the ball anywhere from your thighs to the tips of your toes (or
one toe at a time if you are strong!). Pushup option 2: Put you feet on the ground and your hands on the ball and do pushups. Pushup option 3: Brace the ball against a stationary obeject, put your feet on a weight bench, put a medicine ball on top of the stability ball, and do pushups on the med ball. (This one is a little scary...and hard.)
Shoulder-stands: Put your toes on the ball and pull yourself into a pike position (this itself is a good ab workout). Dip up and down as if doing headstands. This is like doing overhead presses and really hard crunches and balance work at the same time.
Hamstring pullbacks: Lie on the floor and put your heels on the top center of the ball. Cross your arms over your chest, raise your pelvis into a pelvic tilt. Now pull the ball towards you, digging in with your heels. Roll it back out again. Try to keep it going in a straight line. If this gets easy, do it one leg at a time, with the non-working leg held above the ball.
Wall squats with or without dumbbells: We've been doing these one leg at a time, with one dumbbell to throw you off balance. Don't try this if you have knee problems!
Oblique rolls: Put your knees in the center of the ball and your palms on the floor. Roll your body from the waist, so that the side of one thigh is against the ball, hold for a beat, roll the other way. Be prepared to fall off a few times while you get the hang of this one. If you can't do it with your knees on the ball, try doing it with your thighs flat on the ball.
The possibilities are endless! I love stability balls
Mel